/**
* @author AlbertDarren
* @contact 2563491540@qq.com
*/
#include <cstdio>
#include <cmath>
using namespace std;

int main_1026()
{
    double C1,C2,time_delta,hh,mm,ss,CLK_TCK=100;
    scanf("%lf%lf",&C1,&C2);
    time_delta=(C2-C1)/CLK_TCK;
    hh=floor(time_delta/3600);
    time_delta-=hh*3600;
    mm=floor(time_delta/60);
    time_delta-=mm*60;
    ss=round(time_delta);
    printf("%02.0lf:%02.0lf:%02.0lf\n",hh,mm,ss);
	return 0;
}
